The invention relates to a toe unit for safety ski bindings. More particularly, the invention relates to easy withdrawal of the boot in the event of a fall.
This type of toe unit kind is described in several embodiments in U.S. Pat. No. 4,268,064 to Svoboda. With the constructions shown in FIGS. 1-6, the centering of the bolt, in the running position, is effected by means of an elastic compound annularly surrounding the bolt and held in position by a component rigidly fixed to the ski. For example, although the ring shown in FIG. 6 can perform a certain elastic holding function on the bolt, and thereby on the sole retainer, it is nevertheless impossible to lock the bolt, and consequently the sole retainer, in this way through its shape. Hence, this design has the drawback that it is possible for the bolt, and thus for the sole retainer, to swivel even in the course of skiing, that is to say, at a time when the bolt carrying the sole retainer is to be held immovably in position.
By contrast, with the constructions shown in FIGS. 7-15, the bolt is locked by means of cams located on projections of the two bell-crank levers. In the event of a backward-twisting fall, release of the bolt is not possible until one of the bell-crank levers has already been swung to a specific angle by the ski boot of the skier, but this will cause a delay in the reduction of the friction between the sole retainer, and the ski boot.